Which of the following is a typical property of ionic compounds?

• A. They have high melting and boiling points.
• B. They are generally insoluble in water.
• C. They are usually malleable and ductile.
• D. They conduct electricity in solid state.

Answer: (A)

Verified step by step guidance

1. Understand what ionic compounds are: Ionic compounds are formed by the electrostatic attraction between positively charged cations and negatively charged anions.
2. Recall the nature of ionic bonds: These bonds are strong due to the attraction between oppositely charged ions, which affects physical properties like melting and boiling points.
3. Analyze the options given: High melting and boiling points are typical because a lot of energy is needed to overcome the strong ionic bonds in the solid lattice.
4. Consider solubility: Ionic compounds are generally soluble in water because water molecules can stabilize the separated ions, so the statement about insolubility is incorrect.
5. Evaluate electrical conductivity: Ionic compounds conduct electricity when molten or dissolved in water (ions are free to move), but not in the solid state where ions are fixed in place.